1// SPDX-License-Identifier: GPL-2.0-or-later 2/* 3 * processor_perflib.c - ACPI Processor P-States Library ($Revision: 71 $) 4 * 5 * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com> 6 * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com> 7 * Copyright (C) 2004 Dominik Brodowski <linux@brodo.de> 8 * Copyright (C) 2004 Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> 9 * - Added processor hotplug support 10 */ 11 12#define pr_fmt(fmt) "ACPI: " fmt 13 14#include <linux/kernel.h> 15#include <linux/module.h> 16#include <linux/init.h> 17#include <linux/cpufreq.h> 18#include <linux/slab.h> 19#include <linux/acpi.h> 20#include <acpi/processor.h> 21#ifdef CONFIG_X86 22#include <asm/cpufeature.h> 23#endif 24 25#define ACPI_PROCESSOR_FILE_PERFORMANCE "performance" 26 27static DEFINE_MUTEX(performance_mutex); 28 29/* 30 * _PPC support is implemented as a CPUfreq policy notifier: 31 * This means each time a CPUfreq driver registered also with 32 * the ACPI core is asked to change the speed policy, the maximum 33 * value is adjusted so that it is within the platform limit. 34 * 35 * Also, when a new platform limit value is detected, the CPUfreq 36 * policy is adjusted accordingly. 37 */ 38 39/* ignore_ppc: 40 * -1 -> cpufreq low level drivers not initialized -> _PSS, etc. not called yet 41 * ignore _PPC 42 * 0 -> cpufreq low level drivers initialized -> consider _PPC values 43 * 1 -> ignore _PPC totally -> forced by user through boot param 44 */ 45static int ignore_ppc = -1; 46module_param(ignore_ppc, int, 0644); 47MODULE_PARM_DESC(ignore_ppc, "If the frequency of your machine gets wrongly" \ 48 "limited by BIOS, this should help"); 49 50static bool acpi_processor_ppc_in_use; 51 52static int acpi_processor_get_platform_limit(struct acpi_processor *pr) 53{ 54 acpi_status status = 0; 55 unsigned long long ppc = 0; 56 s32 qos_value; 57 int index; 58 int ret; 59 60 if (!pr) 61 return -EINVAL; 62 63 /* 64 * _PPC indicates the maximum state currently supported by the platform 65 * (e.g. 0 = states 0..n; 1 = states 1..n; etc. 66 */ 67 status = acpi_evaluate_integer(pr->handle, "_PPC", NULL, &ppc); 68 if (status != AE_NOT_FOUND) { 69 acpi_processor_ppc_in_use = true; 70 71 if (ACPI_FAILURE(status)) { 72 acpi_evaluation_failure_warn(pr->handle, "_PPC", status); 73 return -ENODEV; 74 } 75 } 76 77 index = ppc; 78 79 if (pr->performance_platform_limit == index || 80 ppc >= pr->performance->state_count) 81 return 0; 82 83 pr_debug("CPU %d: _PPC is %d - frequency %s limited\n", pr->id, 84 index, index ? "is" : "is not"); 85 86 pr->performance_platform_limit = index; 87 88 if (unlikely(!freq_qos_request_active(&pr->perflib_req))) 89 return 0; 90 91 /* 92 * If _PPC returns 0, it means that all of the available states can be 93 * used ("no limit"). 94 */ 95 if (index == 0) 96 qos_value = FREQ_QOS_MAX_DEFAULT_VALUE; 97 else 98 qos_value = pr->performance->states[index].core_frequency * 1000; 99 100 ret = freq_qos_update_request(&pr->perflib_req, qos_value); 101 if (ret < 0) { 102 pr_warn("Failed to update perflib freq constraint: CPU%d (%d)\n", 103 pr->id, ret); 104 } 105 106 return 0; 107} 108 109#define ACPI_PROCESSOR_NOTIFY_PERFORMANCE 0x80 110/* 111 * acpi_processor_ppc_ost: Notify firmware the _PPC evaluation status 112 * @handle: ACPI processor handle 113 * @status: the status code of _PPC evaluation 114 * 0: success. OSPM is now using the performance state specified. 115 * 1: failure. OSPM has not changed the number of P-states in use 116 */ 117static void acpi_processor_ppc_ost(acpi_handle handle, int status) 118{ 119 if (acpi_has_method(handle, "_OST")) 120 acpi_evaluate_ost(handle, ACPI_PROCESSOR_NOTIFY_PERFORMANCE, 121 status, NULL); 122} 123 124void acpi_processor_ppc_has_changed(struct acpi_processor *pr, int event_flag) 125{ 126 int ret; 127 128 if (ignore_ppc || !pr->performance) { 129 /* 130 * Only when it is notification event, the _OST object 131 * will be evaluated. Otherwise it is skipped. 132 */ 133 if (event_flag) 134 acpi_processor_ppc_ost(pr->handle, 1); 135 return; 136 } 137 138 ret = acpi_processor_get_platform_limit(pr); 139 /* 140 * Only when it is notification event, the _OST object 141 * will be evaluated. Otherwise it is skipped. 142 */ 143 if (event_flag) { 144 if (ret < 0) 145 acpi_processor_ppc_ost(pr->handle, 1); 146 else 147 acpi_processor_ppc_ost(pr->handle, 0); 148 } 149 if (ret >= 0) 150 cpufreq_update_limits(pr->id); 151} 152 153int acpi_processor_get_bios_limit(int cpu, unsigned int *limit) 154{ 155 struct acpi_processor *pr; 156 157 pr = per_cpu(processors, cpu); 158 if (!pr || !pr->performance || !pr->performance->state_count) 159 return -ENODEV; 160 161 *limit = pr->performance->states[pr->performance_platform_limit]. 162 core_frequency * 1000; 163 return 0; 164} 165EXPORT_SYMBOL(acpi_processor_get_bios_limit); 166 167void acpi_processor_ignore_ppc_init(void) 168{ 169 if (ignore_ppc < 0) 170 ignore_ppc = 0; 171} 172 173void acpi_processor_ppc_init(struct cpufreq_policy *policy) 174{ 175 unsigned int cpu; 176 177 for_each_cpu(cpu, policy->related_cpus) { 178 struct acpi_processor *pr = per_cpu(processors, cpu); 179 int ret; 180 181 if (!pr) 182 continue; 183 184 /* 185 * Reset performance_platform_limit in case there is a stale 186 * value in it, so as to make it match the "no limit" QoS value 187 * below. 188 */ 189 pr->performance_platform_limit = 0; 190 191 ret = freq_qos_add_request(&policy->constraints, 192 &pr->perflib_req, FREQ_QOS_MAX, 193 FREQ_QOS_MAX_DEFAULT_VALUE); 194 if (ret < 0) 195 pr_err("Failed to add freq constraint for CPU%d (%d)\n", 196 cpu, ret); 197 } 198} 199 200void acpi_processor_ppc_exit(struct cpufreq_policy *policy) 201{ 202 unsigned int cpu; 203 204 for_each_cpu(cpu, policy->related_cpus) { 205 struct acpi_processor *pr = per_cpu(processors, cpu); 206 207 if (pr) 208 freq_qos_remove_request(&pr->perflib_req); 209 } 210} 211 212static int acpi_processor_get_performance_control(struct acpi_processor *pr) 213{ 214 int result = 0; 215 acpi_status status = 0; 216 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 217 union acpi_object *pct = NULL; 218 union acpi_object obj = { 0 }; 219 220 status = acpi_evaluate_object(pr->handle, "_PCT", NULL, &buffer); 221 if (ACPI_FAILURE(status)) { 222 acpi_evaluation_failure_warn(pr->handle, "_PCT", status); 223 return -ENODEV; 224 } 225 226 pct = (union acpi_object *)buffer.pointer; 227 if (!pct || pct->type != ACPI_TYPE_PACKAGE || pct->package.count != 2) { 228 pr_err("Invalid _PCT data\n"); 229 result = -EFAULT; 230 goto end; 231 } 232 233 /* 234 * control_register 235 */ 236 237 obj = pct->package.elements[0]; 238 239 if (!obj.buffer.pointer || obj.type != ACPI_TYPE_BUFFER || 240 obj.buffer.length < sizeof(struct acpi_pct_register)) { 241 pr_err("Invalid _PCT data (control_register)\n"); 242 result = -EFAULT; 243 goto end; 244 } 245 memcpy(&pr->performance->control_register, obj.buffer.pointer, 246 sizeof(struct acpi_pct_register)); 247 248 /* 249 * status_register 250 */ 251 252 obj = pct->package.elements[1]; 253 254 if (!obj.buffer.pointer || obj.type != ACPI_TYPE_BUFFER || 255 obj.buffer.length < sizeof(struct acpi_pct_register)) { 256 pr_err("Invalid _PCT data (status_register)\n"); 257 result = -EFAULT; 258 goto end; 259 } 260 261 memcpy(&pr->performance->status_register, obj.buffer.pointer, 262 sizeof(struct acpi_pct_register)); 263 264end: 265 kfree(buffer.pointer); 266 267 return result; 268} 269 270#ifdef CONFIG_X86 271/* 272 * Some AMDs have 50MHz frequency multiples, but only provide 100MHz rounding 273 * in their ACPI data. Calculate the real values and fix up the _PSS data. 274 */ 275static void amd_fixup_frequency(struct acpi_processor_px *px, int i) 276{ 277 u32 hi, lo, fid, did; 278 int index = px->control & 0x00000007; 279 280 if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD) 281 return; 282 283 if ((boot_cpu_data.x86 == 0x10 && boot_cpu_data.x86_model < 10) || 284 boot_cpu_data.x86 == 0x11) { 285 rdmsr(MSR_AMD_PSTATE_DEF_BASE + index, lo, hi); 286 /* 287 * MSR C001_0064+: 288 * Bit 63: PstateEn. Read-write. If set, the P-state is valid. 289 */ 290 if (!(hi & BIT(31))) 291 return; 292 293 fid = lo & 0x3f; 294 did = (lo >> 6) & 7; 295 if (boot_cpu_data.x86 == 0x10) 296 px->core_frequency = (100 * (fid + 0x10)) >> did; 297 else 298 px->core_frequency = (100 * (fid + 8)) >> did; 299 } 300} 301#else 302static void amd_fixup_frequency(struct acpi_processor_px *px, int i) {}; 303#endif 304 305static int acpi_processor_get_performance_states(struct acpi_processor *pr) 306{ 307 int result = 0; 308 acpi_status status = AE_OK; 309 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 310 struct acpi_buffer format = { sizeof("NNNNNN"), "NNNNNN" }; 311 struct acpi_buffer state = { 0, NULL }; 312 union acpi_object *pss = NULL; 313 int i; 314 int last_invalid = -1; 315 316 status = acpi_evaluate_object(pr->handle, "_PSS", NULL, &buffer); 317 if (ACPI_FAILURE(status)) { 318 acpi_evaluation_failure_warn(pr->handle, "_PSS", status); 319 return -ENODEV; 320 } 321 322 pss = buffer.pointer; 323 if (!pss || pss->type != ACPI_TYPE_PACKAGE) { 324 pr_err("Invalid _PSS data\n"); 325 result = -EFAULT; 326 goto end; 327 } 328 329 acpi_handle_debug(pr->handle, "Found %d performance states\n", 330 pss->package.count); 331 332 pr->performance->state_count = pss->package.count; 333 pr->performance->states = 334 kmalloc_array(pss->package.count, 335 sizeof(struct acpi_processor_px), 336 GFP_KERNEL); 337 if (!pr->performance->states) { 338 result = -ENOMEM; 339 goto end; 340 } 341 342 for (i = 0; i < pr->performance->state_count; i++) { 343 344 struct acpi_processor_px *px = &(pr->performance->states[i]); 345 346 state.length = sizeof(struct acpi_processor_px); 347 state.pointer = px; 348 349 acpi_handle_debug(pr->handle, "Extracting state %d\n", i); 350 351 status = acpi_extract_package(&(pss->package.elements[i]), 352 &format, &state); 353 if (ACPI_FAILURE(status)) { 354 acpi_handle_warn(pr->handle, "Invalid _PSS data: %s\n", 355 acpi_format_exception(status)); 356 result = -EFAULT; 357 kfree(pr->performance->states); 358 goto end; 359 } 360 361 amd_fixup_frequency(px, i); 362 363 acpi_handle_debug(pr->handle, 364 "State [%d]: core_frequency[%d] power[%d] transition_latency[%d] bus_master_latency[%d] control[0x%x] status[0x%x]\n", 365 i, 366 (u32) px->core_frequency, 367 (u32) px->power, 368 (u32) px->transition_latency, 369 (u32) px->bus_master_latency, 370 (u32) px->control, (u32) px->status); 371 372 /* 373 * Check that ACPI's u64 MHz will be valid as u32 KHz in cpufreq 374 */ 375 if (!px->core_frequency || 376 (u32)(px->core_frequency * 1000) != px->core_frequency * 1000) { 377 pr_err(FW_BUG 378 "Invalid BIOS _PSS frequency found for processor %d: 0x%llx MHz\n", 379 pr->id, px->core_frequency); 380 if (last_invalid == -1) 381 last_invalid = i; 382 } else { 383 if (last_invalid != -1) { 384 /* 385 * Copy this valid entry over last_invalid entry 386 */ 387 memcpy(&(pr->performance->states[last_invalid]), 388 px, sizeof(struct acpi_processor_px)); 389 ++last_invalid; 390 } 391 } 392 } 393 394 if (last_invalid == 0) { 395 pr_err(FW_BUG 396 "No valid BIOS _PSS frequency found for processor %d\n", pr->id); 397 result = -EFAULT; 398 kfree(pr->performance->states); 399 pr->performance->states = NULL; 400 } 401 402 if (last_invalid > 0) 403 pr->performance->state_count = last_invalid; 404 405end: 406 kfree(buffer.pointer); 407 408 return result; 409} 410 411int acpi_processor_get_performance_info(struct acpi_processor *pr) 412{ 413 int result = 0; 414 415 if (!pr || !pr->performance || !pr->handle) 416 return -EINVAL; 417 418 if (!acpi_has_method(pr->handle, "_PCT")) { 419 acpi_handle_debug(pr->handle, 420 "ACPI-based processor performance control unavailable\n"); 421 return -ENODEV; 422 } 423 424 result = acpi_processor_get_performance_control(pr); 425 if (result) 426 goto update_bios; 427 428 result = acpi_processor_get_performance_states(pr); 429 if (result) 430 goto update_bios; 431 432 /* We need to call _PPC once when cpufreq starts */ 433 if (ignore_ppc != 1) 434 result = acpi_processor_get_platform_limit(pr); 435 436 return result; 437 438 /* 439 * Having _PPC but missing frequencies (_PSS, _PCT) is a very good hint that 440 * the BIOS is older than the CPU and does not know its frequencies 441 */ 442 update_bios: 443#ifdef CONFIG_X86 444 if (acpi_has_method(pr->handle, "_PPC")) { 445 if(boot_cpu_has(X86_FEATURE_EST)) 446 pr_warn(FW_BUG "BIOS needs update for CPU " 447 "frequency support\n"); 448 } 449#endif 450 return result; 451} 452EXPORT_SYMBOL_GPL(acpi_processor_get_performance_info); 453 454int acpi_processor_pstate_control(void) 455{ 456 acpi_status status; 457 458 if (!acpi_gbl_FADT.smi_command || !acpi_gbl_FADT.pstate_control) 459 return 0; 460 461 pr_debug("Writing pstate_control [0x%x] to smi_command [0x%x]\n", 462 acpi_gbl_FADT.pstate_control, acpi_gbl_FADT.smi_command); 463 464 status = acpi_os_write_port(acpi_gbl_FADT.smi_command, 465 (u32)acpi_gbl_FADT.pstate_control, 8); 466 if (ACPI_SUCCESS(status)) 467 return 1; 468 469 pr_warn("Failed to write pstate_control [0x%x] to smi_command [0x%x]: %s\n", 470 acpi_gbl_FADT.pstate_control, acpi_gbl_FADT.smi_command, 471 acpi_format_exception(status)); 472 return -EIO; 473} 474 475int acpi_processor_notify_smm(struct module *calling_module) 476{ 477 static int is_done; 478 int result = 0; 479 480 if (!acpi_processor_cpufreq_init) 481 return -EBUSY; 482 483 if (!try_module_get(calling_module)) 484 return -EINVAL; 485 486 /* 487 * is_done is set to negative if an error occurs and to 1 if no error 488 * occurrs, but SMM has been notified already. This avoids repeated 489 * notification which might lead to unexpected results. 490 */ 491 if (is_done != 0) { 492 if (is_done < 0) 493 result = is_done; 494 495 goto out_put; 496 } 497 498 result = acpi_processor_pstate_control(); 499 if (result <= 0) { 500 if (result) { 501 is_done = result; 502 } else { 503 pr_debug("No SMI port or pstate_control\n"); 504 is_done = 1; 505 } 506 goto out_put; 507 } 508 509 is_done = 1; 510 /* 511 * Success. If there _PPC, unloading the cpufreq driver would be risky, 512 * so disallow it in that case. 513 */ 514 if (acpi_processor_ppc_in_use) 515 return 0; 516 517out_put: 518 module_put(calling_module); 519 return result; 520} 521EXPORT_SYMBOL(acpi_processor_notify_smm); 522 523int acpi_processor_get_psd(acpi_handle handle, struct acpi_psd_package *pdomain) 524{ 525 int result = 0; 526 acpi_status status = AE_OK; 527 struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL}; 528 struct acpi_buffer format = {sizeof("NNNNN"), "NNNNN"}; 529 struct acpi_buffer state = {0, NULL}; 530 union acpi_object *psd = NULL; 531 532 status = acpi_evaluate_object(handle, "_PSD", NULL, &buffer); 533 if (ACPI_FAILURE(status)) { 534 return -ENODEV; 535 } 536 537 psd = buffer.pointer; 538 if (!psd || psd->type != ACPI_TYPE_PACKAGE) { 539 pr_err("Invalid _PSD data\n"); 540 result = -EFAULT; 541 goto end; 542 } 543 544 if (psd->package.count != 1) { 545 pr_err("Invalid _PSD data\n"); 546 result = -EFAULT; 547 goto end; 548 } 549 550 state.length = sizeof(struct acpi_psd_package); 551 state.pointer = pdomain; 552 553 status = acpi_extract_package(&(psd->package.elements[0]), &format, &state); 554 if (ACPI_FAILURE(status)) { 555 pr_err("Invalid _PSD data\n"); 556 result = -EFAULT; 557 goto end; 558 } 559 560 if (pdomain->num_entries != ACPI_PSD_REV0_ENTRIES) { 561 pr_err("Unknown _PSD:num_entries\n"); 562 result = -EFAULT; 563 goto end; 564 } 565 566 if (pdomain->revision != ACPI_PSD_REV0_REVISION) { 567 pr_err("Unknown _PSD:revision\n"); 568 result = -EFAULT; 569 goto end; 570 } 571 572 if (pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ALL && 573 pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ANY && 574 pdomain->coord_type != DOMAIN_COORD_TYPE_HW_ALL) { 575 pr_err("Invalid _PSD:coord_type\n"); 576 result = -EFAULT; 577 goto end; 578 } 579end: 580 kfree(buffer.pointer); 581 return result; 582} 583EXPORT_SYMBOL(acpi_processor_get_psd); 584 585int acpi_processor_preregister_performance( 586 struct acpi_processor_performance __percpu *performance) 587{ 588 int count_target; 589 int retval = 0; 590 unsigned int i, j; 591 cpumask_var_t covered_cpus; 592 struct acpi_processor *pr; 593 struct acpi_psd_package *pdomain; 594 struct acpi_processor *match_pr; 595 struct acpi_psd_package *match_pdomain; 596 597 if (!zalloc_cpumask_var(&covered_cpus, GFP_KERNEL)) 598 return -ENOMEM; 599 600 mutex_lock(&performance_mutex); 601 602 /* 603 * Check if another driver has already registered, and abort before 604 * changing pr->performance if it has. Check input data as well. 605 */ 606 for_each_possible_cpu(i) { 607 pr = per_cpu(processors, i); 608 if (!pr) { 609 /* Look only at processors in ACPI namespace */ 610 continue; 611 } 612 613 if (pr->performance) { 614 retval = -EBUSY; 615 goto err_out; 616 } 617 618 if (!performance || !per_cpu_ptr(performance, i)) { 619 retval = -EINVAL; 620 goto err_out; 621 } 622 } 623 624 /* Call _PSD for all CPUs */ 625 for_each_possible_cpu(i) { 626 pr = per_cpu(processors, i); 627 if (!pr) 628 continue; 629 630 pr->performance = per_cpu_ptr(performance, i); 631 pdomain = &(pr->performance->domain_info); 632 if (acpi_processor_get_psd(pr->handle, pdomain)) { 633 retval = -EINVAL; 634 continue; 635 } 636 } 637 if (retval) 638 goto err_ret; 639 640 /* 641 * Now that we have _PSD data from all CPUs, lets setup P-state 642 * domain info. 643 */ 644 for_each_possible_cpu(i) { 645 pr = per_cpu(processors, i); 646 if (!pr) 647 continue; 648 649 if (cpumask_test_cpu(i, covered_cpus)) 650 continue; 651 652 pdomain = &(pr->performance->domain_info); 653 cpumask_set_cpu(i, pr->performance->shared_cpu_map); 654 cpumask_set_cpu(i, covered_cpus); 655 if (pdomain->num_processors <= 1) 656 continue; 657 658 /* Validate the Domain info */ 659 count_target = pdomain->num_processors; 660 if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ALL) 661 pr->performance->shared_type = CPUFREQ_SHARED_TYPE_ALL; 662 else if (pdomain->coord_type == DOMAIN_COORD_TYPE_HW_ALL) 663 pr->performance->shared_type = CPUFREQ_SHARED_TYPE_HW; 664 else if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ANY) 665 pr->performance->shared_type = CPUFREQ_SHARED_TYPE_ANY; 666 667 for_each_possible_cpu(j) { 668 if (i == j) 669 continue; 670 671 match_pr = per_cpu(processors, j); 672 if (!match_pr) 673 continue; 674 675 match_pdomain = &(match_pr->performance->domain_info); 676 if (match_pdomain->domain != pdomain->domain) 677 continue; 678 679 /* Here i and j are in the same domain */ 680 681 if (match_pdomain->num_processors != count_target) { 682 retval = -EINVAL; 683 goto err_ret; 684 } 685 686 if (pdomain->coord_type != match_pdomain->coord_type) { 687 retval = -EINVAL; 688 goto err_ret; 689 } 690 691 cpumask_set_cpu(j, covered_cpus); 692 cpumask_set_cpu(j, pr->performance->shared_cpu_map); 693 } 694 695 for_each_possible_cpu(j) { 696 if (i == j) 697 continue; 698 699 match_pr = per_cpu(processors, j); 700 if (!match_pr) 701 continue; 702 703 match_pdomain = &(match_pr->performance->domain_info); 704 if (match_pdomain->domain != pdomain->domain) 705 continue; 706 707 match_pr->performance->shared_type = 708 pr->performance->shared_type; 709 cpumask_copy(match_pr->performance->shared_cpu_map, 710 pr->performance->shared_cpu_map); 711 } 712 } 713 714err_ret: 715 for_each_possible_cpu(i) { 716 pr = per_cpu(processors, i); 717 if (!pr || !pr->performance) 718 continue; 719 720 /* Assume no coordination on any error parsing domain info */ 721 if (retval) { 722 cpumask_clear(pr->performance->shared_cpu_map); 723 cpumask_set_cpu(i, pr->performance->shared_cpu_map); 724 pr->performance->shared_type = CPUFREQ_SHARED_TYPE_NONE; 725 } 726 pr->performance = NULL; /* Will be set for real in register */ 727 } 728 729err_out: 730 mutex_unlock(&performance_mutex); 731 free_cpumask_var(covered_cpus); 732 return retval; 733} 734EXPORT_SYMBOL(acpi_processor_preregister_performance); 735 736int acpi_processor_register_performance(struct acpi_processor_performance 737 *performance, unsigned int cpu) 738{ 739 struct acpi_processor *pr; 740 741 if (!acpi_processor_cpufreq_init) 742 return -EINVAL; 743 744 mutex_lock(&performance_mutex); 745 746 pr = per_cpu(processors, cpu); 747 if (!pr) { 748 mutex_unlock(&performance_mutex); 749 return -ENODEV; 750 } 751 752 if (pr->performance) { 753 mutex_unlock(&performance_mutex); 754 return -EBUSY; 755 } 756 757 WARN_ON(!performance); 758 759 pr->performance = performance; 760 761 if (acpi_processor_get_performance_info(pr)) { 762 pr->performance = NULL; 763 mutex_unlock(&performance_mutex); 764 return -EIO; 765 } 766 767 mutex_unlock(&performance_mutex); 768 return 0; 769} 770EXPORT_SYMBOL(acpi_processor_register_performance); 771 772void acpi_processor_unregister_performance(unsigned int cpu) 773{ 774 struct acpi_processor *pr; 775 776 mutex_lock(&performance_mutex); 777 778 pr = per_cpu(processors, cpu); 779 if (!pr) 780 goto unlock; 781 782 if (pr->performance) 783 kfree(pr->performance->states); 784 785 pr->performance = NULL; 786 787unlock: 788 mutex_unlock(&performance_mutex); 789} 790EXPORT_SYMBOL(acpi_processor_unregister_performance); 791